The invention relates to rear projection screens and light filters, specifically those with a conformable coating over transparent microspheres.
Rear projection screens transmit an image from the back of the screen to the viewer on the opposite side of the screen. The image is affected by the amount of light transmitted by the screen or filter or throughput. Generally, screens and filters have been limited by their construction to the amount of light transmitted through the screen or filter. It is desirable to have construction which would provide increased light throughput.
Generally, rear projection screens have suffered from poor angularity. Angularity is the term used to describe the ability of a viewer to see a good image from the screen or filter at some angles other than those which are ordinary to the screen surface. As the viewer moves to the side of the screen or filter, the image quality is decreased. It is desirable to have screens and filters which have improved angularity.
U.S. Pat. Nos. 5,563,738 and 5,781,344, issued in the name of Vance, relate to light transmitting and dispersing filters having low reflectance. The multi-layer light filters use the addition of optical layers to a basic refractive light filter to allow adjustment of gain, contrast and ambient light rejection of light filters.
This invention relates to a light transmitting filter comprising (a) light absorbing layer having a first and second surface, (b) transparent microspheres embedded in the light absorbing layer and (c) an optically clear, substantially uniform, conformable layer covering the transparent microspheres, wherein the transparent microspheres provide light tunnels through the light absorbing layer. The invention also relates to methods of making the same. The invention also relates to a method of preparing a light transmitting filter comprising the step of laminating a clear substantially uniform conformable layer over transparent microspheres embedded in a light absorbing layer wherein the transparent microspheres form light tunnels through the light absorbing layer. The light transmitting filters of the present invention have improved light throughput and improved angularity.